Rotor for pumps or motors



ROTOR FOR PUMPS OR MOTORS Filed July 29. 1932 3 Sheets-Sheet l INVENTORS'. LAWRENCE F-YEIUNE. BY VVALTEF? FEHHIS.

Oct. 9, 1934. N ET AL 1,976,424

ROTOR FOR PUMPS OR MOTORS Filed July 29. 1932 3 Sheets-Sheet 2 INVENTORS'. LAWR' ENG E FfYuuNs. B]: WALTER ERR'IS.

A TORNEY.

ROTOR FOR PUMPS OR MOTORS Filed July 29. 1952 3 Sheets-Sheet 3 k 46 INVENTORS. LAWRENCE F.YEILING. 42 BYWALTER F RHIS.

"50 46 45 5/ WHOM.

Patented Oct. 9, 1934 PATENT OFFICE ROTOR FOR PUDIPS OR MOTORS Lawrence Franklin Young and Walter Ferris,

Milwaukee, Wis., assignorsto The Oilgear Company, Milwaukee, Wis., a corporation of Wis- Application July 29, 1932, Serial No. 625,756

14 Claims.

This invention relates to rotors for pumps or fluid motors.

The pump or motor to which the invention is particularly adapted is of the type in which a cyl- 5 inder barrel is providedwith radial cylinders, the cylinder barrel rotates upon a shaft or pintle through which liquid flows to and from the cylinders, and pistons are fitted in the cylinders and reciprocated therein by a circular driver which is 19 connected to a shaft and rotates in unison with the cylinder barrel upon an axis eccentric to the axis of the pintle, such as the pump disclosed in Patent No. 1,619,200 issued March 1, 1927 to Walter Ferris. The shaft is connected to a prime mover and drives the rotor when the apparatus is to function as a pump, and liquid is delivered under pressure to the cylinders to drive the rotor when the apparatus is to function as a motor. To simplify the description, the rotor will be described herein as applied to a pump although it is equally applicable to a motor of the same type.

A rotor of this kind ordinarily has a crosshead connected to each of its pistons and fitted between bearing surfaces which extend tangentially of the driver and retain the crosshead at the same distance from the axis of the driver while allowing it to move tangentially thereof.

As the driver and the cylinder barrel are eccentric to each other and rotate in synchronism, retaining the crosshead at the same distance from the axis of the driver will cause the distance between the crosshead and the axis of the cylinder barrel to increase during one-half revolution of the rotor and cause this distance to decrease dur- 5 m the other half-revolution thereof.

Increasing the distance between the crosshead and the axis of the cylinder barrel causes the piston to move outward relative to its cylinder, and decreasing this distance causes the piston to move inward relative to its cylinder. The distance through which the piston moves in each direction, which is the stroke of the rotor, is equal to twice the distance between the axes of the cylinder barrel and the driver.

As the crosshead revolves about the axis of the cylinder barrel, its radius of revolution will increase during the outstroke of the piston and it will move at a gradually increasing linear speed. During the instroke of the piston, its radius of revolution decreases and it moves at a gradually decreasing linear speed.

The forces required to increase and decrease the linear speed of the crosshead are ordinarily designated as tangential accelerating forces and,

5 in the prior rotors of the above type, these forces were transmitted between the crosshead and the ylinder barrel through the pistons with the result that each piston was urged laterally first in one direction and then in the opposite direction, thereby causing abrasion of both the piston and its cylinder and shortening the life of the pump.

Further, these tangential accelerating forces are a prime factor in limiting both the speed and size of the prior pumps due to the fact that these forces increase as the square of the speed of the pump and as the weight and radius of revolution of the crossheads increase.

The present invention has an object to provide a pump or fluid motor with a rotor in which the pistons are relieved from substantially all tangential or lateral forces.

Another object is to transmit all tangential accelerating forces through the cylinders independent of the pistons therein.

Another object is to provide a pump or fluid motor in which no lateral or tangential. forces can be transmitted by the pistons to the crossheads connected thereto.

Another object is to arrange each crosshead intermediate the ends of bearing surfaces through which the accelerating forces are transmitted.

According to the invention in its general aspect, a crosshead is connected to a cylinder for the transmission of tangential forces therebetween without affecting the piston in that cylinder.

The invention is illustrated by the pump rotors shown in the accompanying drawings in which the views are as follows:

Fig. 1 is in part an end view and in part 'a sectional view of a rotor in which the invention is embodied and which has its cylinder barrel journaled upon a pintle through which liquid flows to and from the cylinders, the view being taken approximately upon the irregular line 11 of Fig. 2 and showing one segment of the rotor in end elevation and the other segments thereof progressively broken open to'show certain parts both in full and in section.

Fig. 2 is a longitudinal section taken on a line 2-2 of Fig. 1 and showing the pintle in full and a shaft to which the driver of the rotor is connected.

Fig. 3 is a perspective view of a modified cylinder which may be employed in the rotor.

Fig. 4 is a perspective view of a crosshead and sleeve for use with the cylinder shown in Fig. 3.

Fig. 5 is a view similar to Fig. 1 but showing a difi'erent modification of the invention.

Fig. 6 is a section on the line 66 of Fig. 5.

Fig. 7 is a section through one of the cylinders and its associated parts taken in the plane of the line 7-7 of Fig. 6.

Figs. 1 and 2 The rotor shown is intended for use in a pump having a rotatable drive shaft 1 which extends from the front end of the rotor for connection to a prime mover, and a non-rotatable pintle 2 which extends rearward from the rotor and is adjustable transversely to vary the distance between its longitudinal centerline or axis and the axis of the drive shaft.

The pintle has two segmental ports 3 and formed diametrically opposite each other in its front end and communicating, respectively, with two passageways 5 and 6 which extend longitudinally through the pintle for connection at the rear ends thereof with a hydraulic circuit.

The rotor has a cylinder barrel 7, which is closely fitted upon the pintle, and a driver 8 which rotates the cylinder barrel upon the pintle and is connected to the drive shaft 1 to be rotated thereby.

The driver is rotatably supported in the pump casing by two ball bearings 9 and 10. Bearing 9 has its outer race fitted in the front wall 11 of the pump casing and its inner race fitted upon a hub 12 which is formed upon the front end of the driver and has the drive shaft secured therein. The bearing 10 has its outer race fitted in an annular flange 13, which is formed upon the rear end of the driver, and its inner race fitted upon a bearing support 14 which is carried by a partition or wall of the pump casing.

The cylinder barrel has its hub fitted upon the pintle and provided with five cylinders 15 which extend radially therefrom and are each provided at the inner end thereof with a port 16 to register with the pintle ports 3 and 4 alternate- 1y as the cylinder barrel rotates.

Each cylinder 15 has a hollow or recessed piston 17 fitted therein and reciprocated by a piston pin 18 having a nut or thrust collar 19 fastened r to its inner end and a helical compression spring 20 arranged thereon between the collar 19 and a ring nut or thrust ring 17 which encircles the pin 18 and isthreaded into the outer end of the bore or recess of the piston 1'7 to provide an abutment for the spring 20 and thereby enable the piston pin 18 to draw the piston 17 outward.

The piston 1'7 is moved inward by the piston pin 18 acting through a bearing ball 21 which is arranged within the piston between its head and the inner end of the pin 18 and retained in continual engagement with both by the spring 20.

Clearance is provided between the-thrust collar 19 and the wall of the piston 17 and between the pin 18 and the thrust ring 17' to allow the pin to adjust itself without cramping the piston in the cylinder, the ball 21 allowing the inner end of the pin 18 to move freely transversely of the piston head and the inner end of the pin 18 being ordinarily somewhat concave to retain the ball 21 at or near the axis of the pin.

The outer end of the pin 18 is shouldered and attached to the outer or head end of a tubular sleeve 22 which is fitted upon the outside of the cylinder to reciprocate thereon.

The sleeve 22 is reciprocated upon the cylinder and the push pin and the pistons are reciprocated within the cylinder by a crosshead 23 which is secured upon the outside of the sleeve 22 intermediate the ends thereof. The crosshead may be formed integral with the sleeve but is ordinarily made separate and secured in position thereon as by welding.

The driver 8 has a front plate 24 which is ordinarily circular and carries the hub 12 upon the front thereof, and an annular rear plate or ring 25 which carries the flange 13 upon the rear thereof and is connected to the front plate 24 by five webs 26 each of which is arranged between adjacent cylinders 15 intermediate the axis and the periphery of the driver.

Each web 26 is provided upon its outside with two tangential faces 27 each of which is arranged in alinement with a face 27 on the adjacent web and tangential to a circle which is concentric with the axis of the driver.

Each crosshead 23 has its inner face in engagement with the two alined faces 27 on the adjacent webs 26, and it is held in engagement therewith by a roller bearing 28 arranged between its outer face and a bearing plate 29 which is arranged between the outer edges of the front plate 24 and the rear plate 25 parallel to the alined faces 27 with which the crosshead is in engagement.

The sleeve 22 extends through an opening 30 in the cage of the roller bearing 28 and into an opening 31 in the bearing plate 29. The opening 31 allows the sleeve 22 to move longitudinally of the bearing plate, the opening 30 allows the roller bearing 28 to move relative to the sleeve, and the ends of the opening 30 limit the movement of the roller bearing.

When the axis of the pintle is eccentric to the axis of the drive shaft, the cylinders and the crossheads will revolve about different centers and cause reciprocation of'the pistons in the cylinders. For example, if the axis of the pintle is at the left of the axis of the driver in respect to Fig. l and the drive shaft is rotating the rotor in the direction of the arrow, the pistons shown in the upper part of Fig. 1 will be moved progressively outward. by centrifugal force, by the faces 27 forcing the crossheads outward, or by liquid delivered under pressure to the cylinders, and the pistons shown in the lower 120 part of Fig. 1 will be forced inward by the hearing plates 29 acting upon the crossheads through the roller bearings.

Liquid from the passageway 6 will flow through the ports 4 and 16 into the cylinders in which 125 the pistons are moving outward, and the inward moving pistons will expel liquid from their cylinders through the ports 16 and 3 into the passageway 5.

The bearing surfaces between the sleeves and 130 the cylinders and all other bearing surfaces in the rotor are lubricated by the oil vapor which is created in all pumps of this character, and any liquid which leaks past the pistons into the sleeve is allowed to escape through a drain hole 32 provided in the head of each sleeve.

Rotation of the cylinder barrel and the driver about different axes causes the crossheads to move tangentially in one direction relative to the driver during one-half of each revolution and to move relative to the driver in the opposite direction during the other half of the revolution. Consequently, the crossheads must be accelerated and dece erated in each direction during each revolution, and the forces required 145 to overcome the inertia of the crossheads are transmitted through the sleeves to the cylinders.

These forces, which are ordinarily designated as tangential accelerating forces, varyin accordance with the variations in both the speed and 1 weight of the crossheads, and are a prime factor in limiting both the speed and the size of the prior pumps due to the fact that the crossheads of the prior pumps are attached to the outer ends of the piston rods or piston pins and the accelerating forces caused the outer end of each piston to bear upon one side of the cylinder and the inner end thereof to bear upon the other side of the cylinder.

In the present invention, the accelerating forces are transmitted through the sleeves 22 and no part of the accelerating forces is transmitted through the pistons.

Further, the accelerating forces are transmitted at right angles to the bearing surface upon the cylinder wall and intermediate the ends thereof and do not tend to tilt the sleeve upon the cylinder.

The transmission of the accelerating forces through the cylinder walls independent of the pistons allows the rotor to operate at high speed and to be made in large sizes.

Figs. 3 and 4 The rotor has been shown in Figs. 1 and 2 as having cylindrical sleeves fitted upon the cylindrical outer surfaces of the cylinders but other forms may be employed, such as the substantially rectangular sleeve 22*- and the cylinder 15 shown in Figs. 3 and 4.

The sleeve 22- has two fiat arms 33 arranged parallel to each other, and the cylinder 15 is adapted to be fitted between the arms 33 and is provided upon its opposite sides with fiat parallel bearing surfaces 34 to engage the inner faces of the arms 33.

The sleeve 22 is provided in its outer end with a hole35 to receive the end of the piston pin 18 and is provided intermediate its ends with a crosshead 23 which is similar to the crosshead 23 and is secured to the arms 33 as by welding.

The sleeve and the crosshead function in the manner previously described, and the accelerating forces are transmitted between the crosshead and the cylinder through the arms 33 and the bearing surfaces 34.

Figs. 5-7

The rotor shown in these figures has a driver which is substantially the same as the driver 8 shown in Fig. 1 and is supported and functions in the same manner. Consequently, no description of the driver has been deemed necessary, and it has been designated by the reference numeral 8 and its several parts designated by the same reference numerals applied to the corresponding parts of the driver previously described. It is, however, provided opposite each cylinder with a bearing plate 36 which is irnperforate instead of having an opening 31 as in the case of the bearing plate 29. L

The driver 8 rotates a cylinder barrel 37 which is similar to the cylinder barrel '7 and is journaled upon a pintle 2 identical to the pintle 2 previously described.

The cylinder barrel 3'7 is shown provided with five cylinders 38 which are disposed radially about the pintle 2 and provided at the inner end of each with a port 39 to register with the pintle ports 3 and 4 alternately as the cylinder barrel rotates.

Each cylinder 38 has a hollow or recessed piston 40 fitted therein and provided with a piston rod or push pin 41 which bears against the inner end thereof and against a crosshead 42.

The push pin 41 is smaller in diameter than the bore or opening in the piston 40 and it has each of its ends rounded to permit it to tilt slightly within the piston, the outer end of the push pin being arranged within a recess 43 formed in the crosshead 42 upon the inward side thereof.

The crosshead 42 has its inward face in contact with the alined faces 27 on adjacent webs 26 and its outer face engaged by a roller bearing 44 which is arranged between it and the bearing plate 36 to transmit radial forces from the driver to the crosshead and thence to the push pin.

The roller bearing 44 is retained in position between the crosshead 42 and the bearing plate 36 by a lug 45 which is formed upon the crosshead and extends into a slot 46 formed in the cage of the roller bearing.

The crosshead 42 is connected to the cylinder 38 by a connection or sleeve 47 through which tangential forces are transmitted between the driver and the cylinder barrel independent of the piston 40.

The sleeve 47 is substantially cylindrical and closely fitted for reciprocation upon the outside of the cylinder 38 and is provided at its outward end with a rectangular head 48 which is'fastened by a bolt or rivet 49 through each of its corners to the inward face of the crosshead 42. The sleeve 47 thus transmits all tangential and rotative forces between the crosshead and the cylinder barrel, and none of these forces is applied to or affect the piston which is thus relieved from all cramping forces.

The piston 40 is drawn outward by an anend thereof, and by a substantially rectangular spring washer 51 which is fitted loosely upon the piston at the inner side of the fiange 50 and is arranged in a substantially rectangular recess 52 formed in the outer face of the head 48 diagonally to the outer edges thereof as best shown in Fig. 6.

The piston 40, push pin 41, crosshead 42. sleeve 47 and washer 51 remain in the same position relative to each other but, as the rotor rotates, this entire assembly moves radially relative to the cylinder associated therewith due to the .axes of the cylinder barrel and the pintle being offset from each other.

If the axis of the cylinder barrel and the pintle are offset in the direction shown in Fig. 5 and the rotor is rotating in the direction of the arrow, each piston and crosshead assembly is drawn progressively outward as it moves from left to right through the upper 180 degrees of rotation and is urged progressively inward as it moves from right to left to the lower 180 degrees of rotation.

The pistons in the lower 180 degrees are forced inward by the action of the crosshead 42 upon the push pin 41, as previously described, and the pistons in the upper 180 degrees are drawn outward by the washers 51 bearing upon the bottom of the recesses 52 and upon the inner faces of the flanges 50.

Liquid from the passageway 6 flows through the ports 4 and 39 and fills the cylinders in which the pistons are moving outward, and liquid is expelled through the ports 39 and 3 into the passageway 5 from the cylinders in which the pistons are moving inward, as previously described.

The invention herein set forth is susceptible of various modifications without departing from the 1 scope thereof as defined by the following claims which define the invention as applied to a pump rotor but it is to be understood that the claims cover the invention when applied to the rotor of a motor since the same rotor may be employed in either a pump or a motor.

The invention is hereby claimed as follows:

1. A pump rotor, comprising a rotatable cylinder barrel having a cylinder arranged radial to its axis of rotation, a piston arranged in said cylinder, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel and having a slot arranged therein transverse to the axis of said cylinder, a crosshead fitted in said slot for transmitting radial forces between said piston and said driver to reciprocate said piston as said driver rotates, and a sleeve carried by said crosshead and engaging said cylinder upon the outside thereof to transmit tangential forces between said crosshead and said cylinder independent of said piston.

2. A pump rotor, comprising a rotatable cylinder barrel having cylinders arranged radial to its axis of rotation, a piston arranged in each cylinder, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel and having a slot arranged therein transverse to the axis of each cylinder, a crosshead fitted in each slot for transmitting radial forces between each piston and said driver to reciprocate said piston as said driver rotates, and a sleeve carried by each crosshead and engaging a cylinder upon opposite sides thereof to transmit tangential forces between said crosshead and said cylinder barrel independent of the pistons in said cylinders.

3. A pump rotor, comprising a rotatable cylinder barrel having cylinders arranged radial to its axis of rotation, a piston arranged in each cylinder, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel and having a slot arranged therein transverse to the axis of each cylinder, a crosshead fitted in each slot for transmitting radial forces between each piston and said driver to reciprocate said piston as said driver rotates, and a cylindrical sleeve carried by each crosshead and fitted upon the outside of a cylinder to transmit tangential forces between said crosshead and said cylinder barrel independent of the pistons in said cylinders.

4. A pump rotor, comprising a rotatable cylinder barrel having cylinders arranged radial to its axis of rotation, a piston arranged in each cylinder, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel and having a slot arranged therein transverse to the axis of each cylinder, a crosshead fitted in each slot for transmitting radial forces between each piston and said driver to reciprocate said piston as said driver rotates, and a sleeve carried by each crosshead and engaging a cylinder upon the outside thereof to transmit tangential forces between said crosshead and said cylinder barrel independent of the pistons in said cylinders and having a bearing upon said cylinder at each side of said crosshead.

5. A pump rotor, comprising a rotatable cylinder barrel having cylinders arranged radial to its axis of rotation, a piston arranged in each cylinder, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel and having a slot arranged therein transverse to the axis of each cylinder, a crosshead fitted in each slot for transmitting radial forces between each piston and said driver to reciprocate said piston as said driver rotates, and a sleeve carried by each crosshead and engaging a. cylinder upon opposite sides thereof to transmit tangential forces between said crosshead and said cylinder barrel independent of the pistons in said cylinders and having a bearing upon said cylinder at each side of said crosshead.

6. A pump rotor, comprising a rotatable cylinder barrel having cylinders arranged radial to its axis of rotation, a piston arranged in each cylinder, 9. driver rotatable upon an axis eccentric to the axis of said cylinder barrel, a crosshead for transmitting radial forces between each piston and said driver to reciprocate said piston as said driver rotates, and a cylindrical sleeve carried by each crosshead and fitted upon the outside of a cylinder to transmit tangential forces between said crosshead and said cylinder barrel independent of the pistons in said cylinders and having a bearing upon said cylinder at each side of said crosshead.

7. A pump rotor, comprising a rotatable cylinder barrel having a cylinder arranged radial to its axis of rotation, a piston arranged in said cylinder, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel and driven from an outside source of power to rotate said cylinder barrel in unison therewith and to reciprocate said piston, a sleeve fitted upon the outside of said cylinder to transmit tangential forces between it and said driver independent of said piston and connected to said piston to reciprocate it as said driver rotates, and a crosshead carried by said sleeve intermediate the ends thereof to transmit with said sleeve radial forces to said piston and tangential forces to saidcylinder.

8. A pump rotor, comprising a rotatable cylinder barrel having a cylinder arranged radial to its axis of rotation, a piston arranged in said cylinder, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel and driven from an outside source of power to rotate said cylinder barrel in unison therewith and to reciprocate said piston, a sleeve fitted upon the outside of said cylinder, a crosshead carried by said sleeve intermediate the ends thereof to transmit with said sleeve tangential forces to said cylinder independent of said piston, and a piston pin fastened to the outer end of said sleeve and connected to said piston to reciprocate the same.

9. A pump rotor, comprising a rotatable cylinder barrel having a cylinder arranged radial to its axis of rotation, a piston arranged in said cylinder and provided with a piston pin, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel to reciprocate said piston, a crosshead engaging said driverand said piston pin for urging said piston inward, a connection between said cylinder and said crosshead for transmitting tangential forces therebetween independent of said piston, and means connecting said piston to said connection for moving said piston outward.

10. A pump rotor, comprising a rotatable cylinder barrel having a cylinder arranged radial to its axis of rotation, a piston arranged in said cylinder and provided with a piston pin, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel to reciprocate said piston, a crosshead engaging said driver and said piston pin for urging said piston inward, a sleeve carried by said crosshead and engaging said cylinder for transmitting tangential forces therebetween independent of said piston, and means connecting said piston to said sleeve for moving said piston outward.

11. A pump rotor, comprising a rotatable cylinder barrel having a cylinder arranged radial to its axis of rotation, a piston arranged in said cylinder and provided with a piston pin, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel to reciprocate said piston, a crosshead engaging said driver and saidpiston pin for urging said piston inward, a connection between said cylinder and said crosshead for transmitting tangential forces therebetween independent of said piston, and a coupling washer connecting said piston to said connection for moving said piston outward.

12. A pump rotor, comprising a rotatable cylinder barrel having a cylinder arranged radial to its axis of rotation, a piston arranged in said cylinder and provided with a piston pin, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel to reciprocate said piston, a crosshead engaging said driver and said piston pin for urging said piston inward, a sleeve carried by said crosshead and engaging said cylinder for transmitting tangential forces therebetween independent of said piston, and a spring washer connecting said piston to said sleeve for moving said piston outward.

13. A pump rotor, comprising a rotatable cylinder barrel having a cylinder arranged radial to its axis of rotation, a piston arranged in said cylinder and provided with a piston pin, a driver rotatable upon an axis eccentric to the axis of said cylinder barrel to reciprocate said piston, a

crosshead engaging said driver and said piston pin for urging said piston inward, a sleeve rigidly secured to said crosshead upon the inward side thereof and fitted upon the outside of said cylinder to transmit tangential forces between said crosshead and said cylinder independent of said piston, and means connecting said piston to said sleeve for moving said piston outward.

14. A pump rotor, comprising a rotatable cylinder barrel having a cylinder arranged radial to its axis of rotation, a piston arranged in said cylinder and provided with a piston pin, a driver rotating upon an axis eccentric to the axis of said cylinder barrel to reciprocate said piston, a crosshead engaging said driver and said piston pin for urging said piston inward, a sleeve rigidly secured to said crosshead upon the inward side thereof and fitted upon the outside of said cylinder to transmit tangential forces between said crosshead and said cylinder independent of said piston, and a spring washer connecting said piston to said sleeve for moving said piston outward. mo

LAWRENCE FRANKLIN YOUNG. WALTER FERRIS. 

